A 83.5 g sample of a nonelectrolyte is dissolved in 250.1 g of water. The solution is determined to have a boiling point of 102.3 °C. What is the molar mass of the compound? (Kb for water is 0.510 °C/m).

What is the freezing point and normal boiling point of a solution made by adding 39 mL of acetone, C3H6O, to 225 mL of water? The densities of acetone and water are 0.790 g/cm3 and 1.00 g/cm3, respectively.

A forensic chemist is given a white solid that is suspected of being pure cocaine (C17H21NO4, molar mass = 303.35 g/mol). She dissolves 1.22 0.01 g of the solid in 15.60 0.01 g benzene. The freezing point is lowered by 1.32 0.04C. a. What is the molar mass of the substance? Assuming that the percent uncertainty in the calculated molar mass is the same as the percent uncertainty in the temperature change, calculate the uncertainty in the molar mass. b. Could the chemist unequivocally state that the substance is cocaine? For example, is the uncertainty small enough to distinguish cocaine from codeine (C18H21NO3, molar mass = 299.36 g/mol)? c. Assuming that the absolute uncertainties in the measurements of temperature and mass remain unchanged, how could the chemist improve the precision of her results?

Which solute has the greatest effect on the boiling pointof 1.00 kg of water: 50.0 g of strontium chloride (SrCl2) or 150.0 g of carbon tetrachloride (CCl4) ? Justify youranswer.

What quantity of ethylene glycol, HOCH2CH2OH, must be added to 125 g of water to raise the boiling point by 1.0 C? Express the answer in grams.

a. Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. Lattice Energy Hsoln CaCl2(s) 2247kj/mol 46kj/mol Cal2(s) 2059kj/mol 104kj/mol b. Based on your answers to part a, which ion, Cl or I, is more strongly attracted to water?

A 1.00 mol/kg aqueous sulfuric acid solution, H2SO4,freezes at 4.04 C. Calculate i, the vant Hoff factor,for sulfuric acid in this solution.

Carbon tetrachloride (CCl4) boils at 76.8C and has a density of 1.59 g/mL. (a) A solution prepared by dissolving 0.287 mol of a nonelectrolyte in 255 mL of CCl4 boils at 80.3C. What is the boiling point constant (kb) for CCl4? (b) Another solution is prepared by dissolving 37.1 g of an electrolyte (MM=167g/mol) in 244 mL of CCl4. The resulting solution boils at 85.2C. What is i for the electrolyte?

The organic salt [(C4H9)4N][ClO4] consists of the ions (C4H9)4N+ and ClO4. The salt dissolves in chloroform. What mass (in grams) of the salt must have been dissolved if the boiling point of a solution of the salt in 25.0 g chloroform is 63.20 C? The normal boiling point of chloroform is 61.70 C and Kb = 3.63 C kg mol1. Assume that the salt dissociates completely into its ions in solution.

Concentrated hydrochloric acid contains 1.00 mol HCl dissolved in 3.31 mol H2O. What is the mole fraction of HCl in concentrated hydrochloric acid? What is the molal concentration of HCl?